BIO Water Recycling

German Patent

Description of the Process

BIO Water is a system
combining the treatment of recycled water and process water especially
designed to meet high demands of the process water quality for running
car wash plants, repair work facilities and high pressure devices. It
further enables the simultaneous treatment of otherwise „critical“ waste
water, e.g. from washing motors of from the workshop area.
1. Fresh water requirement The use of fresh water within a car wash
plant constitues a major cost factor which due to the steady rise of
fresh water and waste water rates will continue to increase during the
years to come. In connection with the BIO Water Systems the wast water
flow from the wash hall is treated and made available as process water
for the actual car wash. The wash components with the highest water
consumption such as brush wash and foam application are carried out by
recycled water. Fresh water is only required for the rinsing and wax
finish stages. The BIO Water Systems ensure a recycled water volume of
at least 80 % and completely odour-free process water, provided that
biologically sound cleaning agents are used in standard wash
process.
2. Waste water The majority of vehicle wash plants are indirect
polluters, i.e. waste water is discharged into the public sewage
disposal plant. The maximum pollutant values for waste water produced
fall under the jurisdiction of the local waste water bylaws. The
permissible maximum values as specified by the waste water legislation
may therefore sometimes differ from the minimum requirements laid down
in the waste water administration regulations (VwV-annex 49) and in the
technical wast water association (AVT A 115). The BIO Water guarantees
that the values for waste water dicharged into the canalization remain
well under the legally permissible maximum values. The BIO Water Systems
are a truly long-term investment and will meet even more stringent
environmental regulations in the years to come. 3. Specifications of the
water processing The BIO Water Recycling Systems as described below are
designed individually for each project and are brought into line with
the required process water volume.

The waste water from the washing area of the wash
plant, high pressure devices as well as from ball valves in the workshop
is fed into the biological sludge trap (min. of 2 x 5 cbm). By means of
a submersible pump the required process water is fed from the second
sludge trap into the top level „activation tank“ and flows back into the
first sludge trap via the overflow. Specially adapted microorganisms are
added to the whole recirculating system to further improve the process
water quality by the biological decomposition of possibly existing
carbon hydrates and tensides. The solid components of the crude waste
water from the second sludge trap are separated in the „activation unit“
by means of a special sieve with conical gaps and are collected in a
filter hose with removable filter cartridge. The filter is drained into
the first sludge trap. The waste water to be biologically purified in
the BIO Water sludge process is highly oxygenated and dirt particles are
floated off with a clear water zone rich in oxygene being achieved in
the BIO Water. An installed fluidized bed serves to enlarge the
settlement area of microorganisms thus increasing the biological
decomposition of pollutants. Clean process water is drawn off from the
clear water zone by means of pressure pump and fed into the process
water storage tank via a subsequent filter device (separation grade 80
ym). The filter capacity is permanently monitored and the SPC display
indicates if the washable filter cartridge has to be replaced. The clean
process water for high-pressure pre-cleaning, underbody wash, foam
application and brush wash in the car wash plant and/or for pre-cleaning
and brush wash in the self-service wash facilities can be taken from the
process water storage tank whereas for rinsing and wax application fresh
water is required. If no process water is withdrawn, the basin is
periodically emptied and the water is fed into the sludge trap. In case
of process water shortage a solenoid valve automatically controls the
feeding of fresh water into the basin. The volume of recycled process
water achieved in the wash area is mainly determined by the combination
of wash programmes. A recycling rate of process water of up to 80 % has
been achieved in similar applications. According to the legal
regulations a fuel separator has to be installed to prevent any oil or
fuel accidents. Local waste water bylaws may even prescribe the in-line
installation of a coalescence separator. As a rule subsequent
adjustments can be carried out without additional digging work provided
that empty pipes run from the pile basin to the installation site of the
plant for the recycling of process water. There are two alternatives for
the underground layout of the tanks: Two subsequently installed sludge
receiver and a fuel/ coalescence separator or sludge receiver -
fuel/coalescence separator - pile basin. Option: Stationary sludge
removal The sludge removal system, available as option, consists of an
additional mixer-pump and a submersible pump which are installed in the
first activated sludge tank where most of the sludge is accumulated. The
sludge is removed at night. The accumulated sediments are whirled up by
the mixer-pump and pumped to the activated sludge tank of the BIO Water.
The sediments in the activated sludge tank are separated from the crude
waster water by means of a special sieve with conical gaps and fed into
a filter system. Here, the sludge is drained via a compressed air
membrane pump into a filter hose with the filtrate being fed back into
the first sludge trap. The sediments from the sludge trap are compacted
in the filter cartridges and are regularly dicharged in mobile tanks by
a specialized sludge disposal company.